Commercial process for reclaiming the dye content of waste liquors.



T. FORSYTH COMMERCIAL PROCESS FOR RECLAIMENG THE DYE CONTENT OF WASTE LLQUORS.

APPucumu mu) 95C. I, was

1,242,676. Patented Oct. 9. 1917.

ammo to:

QXRh wmwa 720/1106 Enyfk f 4 MM r/bwz i Mm/64wd. dot/ 24.

UNITED STATES PATENT OFFICE.

IHOMAS FoRsYTH, on NEW HAVEN. dbmracmm, assiqnon 71:10 .THE FORSYTH DYEING 00., OF NEW HAVEN, CONNECTICUT, A CORPORATION OF CONNECTICUT.

COMMERCIAL PROCESS non RECLAIMING THE DYE coNTENT (s s-wast Lmuons.

Specification of Letters Patent.

' ramamaoctfia, 191 7.-

Application filed December 1, 1916. Serial R0. 134.27%.

liquors produced in commercial dyeing with sulfur colors has been lost, with the result that thenet-cost of dyein with such colors has'included the cost of the entire dye-content, that unappropriated and lost as well as that actually taken up by the goods.

Theobject of this invention is to recover for re-use the unappropriated or unused portion of this dye-content from the waste waters.

A. further object of the invention is to provide a method wherebythis process may he carried on continuously if desired.

The invention further consists in the provision of a process whereinthe precipitated dye stuii' may be collected and deposited on filtering screens located over a precipitationtank to drain hack thcreinto so that any of the dye-content which may pass through the filtering screens will he again collectedin the precipitation-tank and again epositedon the screens thereby reducing the loss in the final discharge aters to the minimum.

By the use of my commercial process two essential advantages are obtained; firshthat portion of the dye stuff which is not tallied up by the goods is reclaimed to he used again, thus materially reducing the cost (if dyeing over the old method, which is that;

of permitting this unused dye stuff to pass with the wash waters into the nearby streams and rivers: second, by removing this dye stuff from the waste wvater before permitting it to escape, is of great public enefit as it prevents these highly colored and malodorous liquors prodileed in dyeing with sulfur colors, from polluting t;h e streams and other wafers and ltillingi of the animal life therein and the rendering sanitary and olrim-tiolulhlev tlwfjneighborfiing territory. I J

\Vith these ends in View;my iintqention consists in a process of recovering the Clyc content of'the wash ataters, waste d v e baths. and the like. producedi n dyeing ith sulfur colorsgthc said iroc'feissvcorisis'ting in treating sii'ch'na'ste (")Fivash Waters; and the like with a substance that fllljfil'zlh izcs tl'lttSOlVEllL' effect ohtlieallgal'iiic sullid initially used 'for rendering the sulfur dye 'stufl' soluble in water u'hereby the sulfur dye 'stuff is again rendered insoluble after which it isjreclaimed fron'i'the itate r as' insoluble sulfui-dye'stufi'.

' Vlith these andother objects. in vieiv:

invention, consists of certain new; jeat ures as will be more 'ft'ully "described, and ,par;

tieularly pointed out in tie appended claims.

In the accoinpanying drawing;

Figure 1 is a diagranniiatic' view of an apparatus capable of carrying out the different steps of the inven tionfil.

Fig. 2+ is a side elevatihii gi f the precipitatioli t'ank showing the ova-new and. the well from which the recipit te is collected and removed to he Q epositefl i n the filten "screens. y I Fig."3 is aperspectiveyi form'of filter screens. a V a it.

Since the object bf my method isto neutralize the solvent effect of the alkaline sulr titl initially usedfor renderingthe sulfur dye stufl solulile. I may use an acidhub stance or a metallic salt torv this purfi'ose,

n t showing one or if'desirifd I may blow alr -l ndert-pgessure into theliquor to obta n. this neutralization effect. x y

In practising my invention by the use of an acid substance, afsumcient amount thereo l is "Introduced into the wash waters to throw the dye-content thereo f from soluti on, after which the no insoluble dye-content is recoyered by filtration. plrecipltation, or in sonic other suitable way. he dye stutt liquids,

thus recovered is substantially identical in chemical character with the original dye sluti'. .On account of its chcapness and ellieieney, I prefer to employ ordinary sulfuric acid which. however, I may replace by bydrochloric or some other acid, or in place of the acid I may employ an acid compound such, for instance. as bisulfate of sodium, or iii-sulfate of potassium or some other acid salt. in some cases as stated above I may inject air into the wash waters which when well mixed .with the solution also serves to neutralize. the solvent clien of the solvent employed.

In carrying out my improved process the Waste or wash waters are drawn from the machine or other ll'llPlllF-lt! in which the work was subjected to the dyeing liquor, by opening the valve 11 permitting this waste to pass through the ronduit 12 on its way to the precipitation tank presentlydescribed. The liquor may be caused to pass through this conduit either by the action of a pump or by gravity.

Preferably after the liquor has entered the conduit, I introduce therein a suflicicnt amount of metallic salt or other neutralizing agent from the container 13 to thoroughly neutralize the solvent, which neutralizing agent enters the conduit through the inlet 14. In other instances I admit air from the pressure tank 24 through the pipe 25 into these waste or \vash waters, which air upon being thoroughly mixed with these waters dye stuff, which oxidization neutralizes the solvent and releases the dye stuff from solation.

The mixture of wash waters containing its neutralizing agent now passes on through tlieconduit and is deposited into the mixing' tank [5 which provided with impediments such as a bed of jagged rocks or other suitable means which serves to agitate and mix the hautralizing a at as the liquid ,is forced or passes over amfiiround the same.

After passing through this agitating receptacle the liquor is deposited into the precipitation tank 23. which is provided with flaring drip boards 16 over which the filter screens 17 are located.

This preei )itation tank is also preferably provided wit an illl'llllcfl bottom portion 18 and a well 19 in which the precipitate collects to be drawn therefrom. either intermittently or continuously by a pain 20 and distributed by means of the head lil'into the different filter screens 17 above the tank. Instead of a pump for this urpose the precipit'atc may he collected y any suitable means and subsequently deposited on the lil' ter screens.

These filter screens a! .lllustraterl in Fi 3 are preferably in rows of looped screen 0 oth oxidizes the sulfid used in dissolving the liquor, and

hung on beams above the tank and over its,

flaring, drip boards, whereby the drip from these screens witlrsueh dye-content as may work therethrough falls back into the tan where it. will eventually again find its way into the well 19 to be again removed, deposited and collected on the screenbed. It, is; obvious that the screen eloth which is well known in the art. is orous and that the pores thereof assist inx irawing the moisture from the sludge by on iillary attraction. 'Ihus the sludge is filter b gravity and is subjected to evaporation y atmospheric action.

It will be noted that the waste waters from this precipitation tank after the dyecontcnt. has settled, is permitted to over-flow the upper edge of the tank as at 21 into the waste conduit 22 which waste water is now entirely cleaned of its dye-content and may be discharged into streams or rivers without. detrimental ell'eet.

My improved process, in addition to furnishing a commercial means whereby a valuable dye-content of Wash waters, waste liquors and dye baths produced in dyeing with sulphur colors may be reclaimed and saved at very small cost, is also of great pub lic benefit inovcrcoming to a large degree the pollution of streams and other waters into which the waste with its highly colored and malodorous liquors has been emptied.

I claim:

.1. An improved process of reclaiming the dye contents of waste dye liquors compris ing drawing oil the waste liquors from the dyeing receptacle, incorporating a neutralizlug; agent into the liquor as it flows from said receptacle, then agitating the liquor while flowing to thoroughly incorporate said neutralizing agent. and finally filtering said liquor.

2. An improved process of reclaimingthe dye contents of waste d e liquors com rising drawing of? the waste iquors from t e dyeing receptacle, incorporating a neutrallzl-ng agent. into the liquor as it flows from said receptacle, impeding the flow of the liquor at a plurality of irregularly disposed polnts to agitate the. liquor while flowing, whereby thorough incorporation of said neutralizing agent is effected, and finally filtering said liquor.

3. An improved process of reclaiming the dye contents of waste dye liquors consisting in incorporating a neutralizing agent into the liquor. etlectin a preliminary separation of the recipitated sludge from the nally filtering the sludge by gravity and subjecting the same to ova oration y atmospheric action while eing filtered.

4. An improved process of reclaiming the dye contents of waste dye liquors comprising drawing .011 the waste liquors from the dye- In testimony whereof I aflix my signetuie ing receptacle incorporating a neutralizing in presence of two witnesses.

agent into said liquor, then agitating the THOMAS FORSYTH. liquor to thoroughl incorporate said new Witnesses: 5 tralizing agent, an finally separating the WILLIAM H. FonsYTH,

precipitated sludge from the liquor. CHARLES R. WHEDON. 

